This chapter describes how to set a scale and measure distances and areas on satellite images. Using ImageJ, a freely available image analysis program that runs on most operating systems, users set the spatial calibration of an image, then select...(View More) and measure distances and areas on it. The measurement results are reported in real-world units. The technique is most useful and accurate for nadir view (straight down) images. In this chapter, users examine satellite images of the Aral Sea, which has shrunk dramatically since 1960 because the rivers that flow into it have been tapped for irrigation. Users access satellite images of the region, then set a scale and measure the width of the sea each year. On another set of images, they highlight areas that represent water and measure them to see how these areas of the sea changed. This chapter is part of the Earth Exploration Toolbook, which provides teachers and/or students with direct practice for using scientific tools to analyze Earth science data. Students should begin on the Case Study page.(View Less)

El Niño impacts sea surface height, sea surface temperature and wind vectors. In this lesson, data for each of those three characteristics from the 1997-98 El Niño event will be analyzed and compared. Students will work in teams of 3 throughout...(View More) the activity, initially doing a team analysis of a single characteristic, and then jig-sawing into other groups to share information. The lesson culminates in a series of questions, a written summary and a comparison to similar observations done by scientists. This lesson uses student- and citizen science-friendly microsets of authentic NASA Earth system science data from the MY NASA DATA project. It also includes related links, extensions, an online glossary, and a list of related AP Environmental Science topics.(View Less)